Video Experimental Relacionado
Updated: Jul 12, 2026
10:28
Investigating the Relationship between Sea Surface Chlorophyll and Major Features of the South China Sea with Satellite Information
Published on: June 13, 2020
La evolución estacional del cloro reactivo en la estratosfera del hemisferio norte
Science (New York, N.Y.)
|August 27, 1993
Resumen
Los niveles de monóxido de cloro (ClO) aumentaron dentro del vórtice polar durante el invierno de 1991-1992, lo que indica un agotamiento significativo de la capa de ozono. El monte Pinatubo es el monte Pinatubo.
Área de la Ciencia:
- Química de la atmósfera química de la atmósfera
- Investigación de la capa de ozono Investigación de la capa de ozono.
- Ciencias Polares Ciencias Polares.
Sus antecedentes:
- El agotamiento del ozono es una preocupación ambiental significativa.
- El monóxido de cloro (ClO) es un radical clave en la destrucción del ozono.
- La erupción del Monte Pinatubo en 1991 impactó en la química atmosférica.
Objetivo del estudio:
- Informar las mediciones in situ del monóxido de cloro (ClO).
- Para investigar el comportamiento del ClO dentro del vórtice polar durante el invierno.
- Para evaluar el impacto de los aerosoles volcánicos en la composición atmosférica.
Principales métodos:
- Se llevaron a cabo mediciones in situ de ClO.
- Los datos se recogieron de octubre de 1991 a febrero de 1992.
- Las observaciones se realizaron en latitudes medias y altas del norte.
Principales resultados:
- Se observaron mejoras significativas de ClO dentro del vórtice polar después de que las temperaturas cayeron por debajo de 195 K.
- Las disminuciones de ClO en febrero se correlacionan con la formación de nitrato de cloro (ClONO ((2)).
- Las elevadas abundancias de ClO fuera del vórtice se relacionaron con la supresión de NOx de los aerosoles del Monte Pinatubo.
Conclusiones:
- El estudio confirma el papel del ClO en el agotamiento del ozono polar.
- Los aerosoles volcánicos influyeron significativamente en los niveles atmosféricos de NOx y las concentraciones de ClO.
- La comprensión de estos procesos es crucial para predecir la futura recuperación de la capa de ozono.
Videos de Conceptos Relacionados
01:31Radical Substitution: Allylic Chlorination
Typically, when alkenes react with halogens at low temperatures, an addition reaction occurs. However, upon increasing the temperature or under reaction conditions that form radicals, providing a low but steady concentration of halogen radicals, allylic substitution reaction is favored. This is because allylic hydrogens are very reactive as the formed intermediate is resonance stabilized. For example, when propene is treated with chlorine in the gas phase at 400 °C, it undergoes allylic...
01:27Radical Substitution: Halogenation of Alkanes and Alkyl Substituents
In the presence of heat or light, alkanes react with molecular halogens to form alkyl halides by a substitution reaction called radical halogenation. This reaction has three steps: initiation, propagation, and termination, as seen in the radical chlorination of methane to produce methyl chloride.
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...
01:22Mass Spectrometry: Alkyl Halide Fragmentation
Chlorine isotopes exist as 35Cl and 37Cl in a 3:1 ratio, while bromine isotopes exist as 79Br and 81Br in a 1:1 ratio. The mass spectrum of alkyl halides typically produces two distinct molecular ion peaks, the molecular ion peak, [M], and the molecular ion plus two, [M + 2] peak. The relative heights of these two peaks are proportional to the isotopic abundance ratios of the halide. For example, 2‐chloropropane and 1‐bromopropane display two peaks with relative peak heights in a 3:1 and 1:1...
01:33Radical Halogenation: Stereochemistry
Stereochemistry is the study of the different spatial arrangements of atoms in a given molecule. The stereochemistry of radical halogenations can be understood from three different situations:
Halogenation to form a new chiral center:
Halogenation to form a new chiral center:
01:18Carboxylic Acids to Acid Chlorides
Carboxylic acids react with SOCl2 or PCl5 to form acid chlorides. Amongst the carboxylic acid derivatives, acid chlorides are the most reactive and synthetically important derivatives. They are useful reagents for Friedel–Crafts acylation of some aromatic compounds.
02:46Halogenation of Alkenes
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.